马新仿 非常规油气藏复杂缝网压裂机理

断块油气田FAULT-BLOCK OIL&GAS FIELD第28卷第1期2021年1月doi:10.6056/dkyqt202101010三塘湖盆地致密油水平井增能压裂力学机理郭建设#，2,周福建D,胡晓玲“,刘雄飞D,王博D"1.东北石油大学石油工程学院，黑龙江大庆163318；2•中国石油吐哈油田分公司，新疆哈密838202；3.中国石油大学(北京)非常规油气科学研究院，北京102249；4.中国石油西部钻探工程有限公司地质研究院，新疆克拉玛依834000)基金项目：国家科技重大专项课题“低渗油气藏钻井液完井液及储层保护技术"(2016ZX05021-004)摘要重复压裂是三塘湖盆地油藏提高产能和采收率的必备手段&文中通过基于黏聚层单元的有限元数值模拟、室内岩石力学实验、j发射监测和岩石力学屈服破坏准则理论等手段，系统研究了该区块重复压裂改造中的增能力学机理&研究结果表明：增能压裂的核心是提升全局范围内地层孔隙压力，而暂堵转向是局部范围提升已有裂缝内的净压力，二者配合使用，使整体压力和局部净压力提升，在较大范围内激活天然裂缝系统&增能压裂的应力应变曲线特征、j发射特征呈现多次起伏波动和多次破裂特征，破裂压力相对较低&增能压裂裂缝扩展参数与地层孔隙压力提升比例、岩石力学参数及水岩相互作用时间等因素密切相关，其孔隙压力增加存在某一最优化值&关键词致密油；水平井；重复压裂；增能；力学机理中图分类号：TE357.1文献标志码：AMechanical mechanism of horizontal well energized fracturing of tight oil inSantanghu BasinGUO Jianshe1-2,ZHOU Fujian3,HU Xiaoling4,LIU Xiongfei3,WANG Bo C(l.Northeast Petroleum University,Daqing16331&China;2.Tuha Oilfield Company,PetroChina,Hami838202,China;C.Unconventional Petroleum Research Institute,China University of Petroleum,Beijing102249,China;4.Geological ResearchInstitute of CNPC Xibu Drilling Engineering Company Limited,Karamay834000,China) Abstract：The refracturing stimulation is the necessary means to improve the reservoir productivity and recovery in Santanghu basin.In this paper,by means of finite element numerical simulation based on cohesive zone,the rock mechanics experiment in the laboratory,acoustic emission monitoring and the related Mohr-Coulomb yield failure criterion theory,the energized mechanical mechanism in the refracturing of this area is systematically studied.The result shows that the core of energized fracturing is to increase the pore pressure of the formation in the global scope,while the temporary plugging and diverting are to locally increase the net pressure in the existing cracks.The two methods are used together to make the overall pressure and the net pressure increased, which will activate the natural fracture system in a large range.The stress-strain curve and acoustic emission characteristics of energized fracturing show multiple fluctuations and multiple rupture characteristics,and the rupture pressure is relatively low.The parameters of crack propagation in energized fracturing are closely related to those factors such as the increase ratio of formation pore pressure,rock mechanics parameters and water-rock interaction time.There is also an optimum value for pore pressure increase.Key words：tight oil;horizontal well;refracturing;energization;mechanical mechanism孔隙度为16.5%,平均渗透率为0.2%10[3!m2；天然裂缝发育密度为33条/m,方解石充填、半充填；油藏压力0引｝三塘湖盆地位于新疆维吾尔自治区的东北部，盆地内致密油区块主要集中在马朗凹陷，已发现二叠系条湖组、芦草沟组2套致密油层。

页岩气藏水力压裂渗吸机理数值模拟研究雷征东;覃斌;刘双双;蔚涛【摘要】To better understand the imbibition behavior in shale reservoirs during production and hydraulic fracturing operations,we investigated the imbibition mechanism and evaluated the formation damage resulting from imbibition.This paper first presents a hydro-mechanical model for a shale gas reservoir with consideration for multiple flow regimes,gas diffusion and desorption,stress sensitive effect,and capillary pressure.Then the formation damage caused by the imbibition mechanism is evaluated by quantifying facture face skin evolution during fracture cleanup and subsequent production.The simulation results indicate that (1) the imbibition has a huge influence on reservoir performance in well tests and production periods,and a high capillary pressure is the main cause behind the imbibition phenomenon and water blockage around hydraulic fractures;(2) it is possible to obtain the original gas pressure by detecting the fracture pressure of new wells with hydraulic fracturing stimulation;(3) formation damage caused by wetting phase trapping is one of the main causes impairing well productivity hydraulic fracturing of tight gas reservoirs,which should not be neglected.This research provides a theoretical foundation for a better understanding of reservoir performance of shale gas,especially for optimizing production by reducing formation damage caused by imbibition at an early period.%针对页岩储层在水力压裂作业和生产中渗吸机理及作用规律不清的问题,开展了渗吸机理及其引起的地层伤害评估的研究.建立了考虑不同影响因素的页岩水力压裂渗吸数学模型,包括基质和裂缝流动,气体扩散和解吸,应力敏感效应和毛细管压力,然后,讨论了在压裂气藏和后续生产期间如何通过量化裂缝面表皮演变来评估由于渗吸机制导致的储层伤害现象.结果表明,(1)在试井以及生产阶段渗吸对储层特性有较大影响,极大的毛细管压力是导致渗吸现象和水力裂缝附近水封的主要原因;(2)对于实施了水力压裂增产措施的新井通过探测裂缝压力可以获得原始气体压力;(3)润湿相阻塞导致的储层伤害是影响致密气藏水力压裂井生产能力的主要来源之一.研究结果对于页岩气藏的渗流特性能够提供深刻的理解,尤其是为早期生产阶段降低由渗吸作用可能造成的储层伤害来优化生产提供理论依据.【期刊名称】《西南石油大学学报（自然科学版）》【年(卷),期】2017(039)002【总页数】7页(P118-124)【关键词】数值模拟;渗吸机理;页岩气;水力压裂;毛细管压力【作者】雷征东;覃斌;刘双双;蔚涛【作者单位】中国石油勘探开发研究院,北京海淀100083;保利协鑫石油天然气集团控股有限公司,北京东城100010;中国石油勘探开发研究院,北京海淀100083;中国石油勘探开发研究院,北京海淀100083【正文语种】中文【中图分类】TE312雷征东，覃斌，刘双双，等.页岩气藏水力压裂渗吸机理数值模拟研究[J].西南石油大学学报（自然科学版），2017，39（2）：118-124.LEI Zhengdong,QIN Bin,LIU Shuangshuang,et al.Imbibition Mechanism of Hydraulic Fracturing in Shale Gas Reservoir[J].Journal of Southwest Petroleum University(Science&Technology Edition),2017,39(2):118–124.渗吸是两相或者多相体系中与驱替有关的重要流体流动现象。

杂裂缝分形维数测定的统计方法——基于盒数法的网格覆盖法，对数值模拟的压裂效果进行评价。结果表明：天
然裂缝的发育程度与压裂改造效果关系密切，水力裂缝遇天然裂缝发生分叉，并沿天然裂缝扩展滑移或直接穿过
天然裂缝，形成复杂水力裂缝及复杂压裂缝网；天然裂缝发育密度越大，其迹长越长，水力裂缝的分形维数越大，对
裂缝性储层改造效果越好。
Abstract：Hydraulic fracturing technology is an important method to increase oil and gas production. In reservoirs such as shale and sandstone，different degrees of natural fractures develop. When hydraulic fracturing is used for fractured reser⁃ voirs，the existence of natural fracture has a significant impact on the formation and development degree of hydraulic frac⁃ ture，especially for fracture network. In order to analysis the rock failure process，a two-dimensional plane-strain calcula⁃ tion model based on the FEM（finite element method）was established considering the development of natural fractures. The formation process of hydraulic fractures and complex fracture network in the hydraulic fracturing process were re⁃ searched，and its influencing factors were analyzed. Grid-coverage method based on box counting method was introduced to measure the fractal dimension of the complex reservoir fractures and the fracturing effect obtained by numerical simula⁃ tion was evaluated. The simulation results suggest that the development of natural fractures definitely affects the produced fractures.When propagating near natural fractures，hydraulic fractures will bifurcate，slip along the natural fracture for ex⁃ tension，or directly propagate through the natural fractures in its previous direction，and form a complex hydraulic fracture or a fracture network. Dense natural fractures with larger trace length can result in larger fractal dimension of hydraulic frac⁃ tures and better reformation effect of the fractured reservoirs.

◄油气开发►doi:10.11911/syztjs.2024012引用格式：张衍君，王鲁瑀，刘娅菲，等. 页岩油储层压裂–提采一体化研究进展与面临的挑战[J]. 石油钻探技术，2024, 52（1）：84-95.ZHANG Yanjun, WANG Luyu, LIU Yafei, et al. Advances and challenges of integration of fracturing and enhanced oil recovery in shale oil reservoirs [J]. Petroleum Drilling Techniques ，2024, 52(1)：84-95.页岩油储层压裂–提采一体化研究进展与面临的挑战张衍君1， 王鲁瑀2， 刘娅菲1， 张佳亮3， 周德胜1， 葛洪魁3（1. 西安石油大学石油工程学院, 陕西西安 710065；2. 香港理工大学土木及环境工程系, 香港 999077；3. 中国石油大学（北京）非常规油气科学技术研究院, 北京 102249）摘　要: 页岩油储层压裂开发中，以远超地层吸收能力的注入速率向储层注入包含各类添加剂的工作液，基本完成了压裂介质一次注入、油井开发全生命周期受益的使命。

其中，2个问题尤为关键：1）如何形成均匀展布的裂缝网络，增大裂缝和储层的接触面积、提高液体流动效率？2）在形成高效传压传质缝网的基础上，存地压裂液如何提高储层中原油的可动性？压裂和提采一体化是解决上述问题的重要思路。

为此，阐述了页岩油储层压裂–提采一体化的内涵，归纳了实现压裂–提采一体化的模拟和试验技术；明确了页岩油储层压裂–提采一体化的科学问题：均衡应力压裂形成均匀展布的缝网，提高均布缝网中流体流动与传输的效率，强化基质孔隙中油气的动用。

同时，指出了压裂–提采一体化面临的挑战：明确裂缝非均匀扩展导致的压裂井间干扰机理并建立控制方法，形成裂缝中高压流体高效作用于基质孔隙的途径，揭示压裂液–储层–原油相互作用提高原油可动性机理。